Classic Resources To Achieve The Elusive Female Orgasm

Q. I have a friend who does not live in the area who has never been able to orgasm with a partner — she can only achieve an orgasm thru masturbation (by “grinding” on a pillow) — but wants to be able to orgasm with her partner. Since my friend does not live nearby, I was hoping you might be able to suggest a book or two that might help her.